This week, scientists announced a study that demonstrates a blood test that can detect advanced-stage prostate cancer. The study, from researchers at the Spanish National Cancer research Centre (CNIO), Institute for Cancer Research, and the Royal marsden NHS Foundation Trust, was published this week in the journal Lancet Oncology.

The new test studies genetic patterns in blood cells, which can then be used with current prostate-specific antigen (PSA) tests to classify patients most in need of treatment. Often, patients may live with prostate cancer for years without showing any symptoms, but other tumors, according to the researchers, can be “very aggressive and deadly.” Their new test can help identify these different types of patients.

The study scanned the genes in the blood samples of 100 prostate cancer patients. 69 of the patients had advanced stage prostate cancer, while 31 of them had a low-risk tumor. The researchers split the patients into four groups based on their different genetic activity patterns, which they describe as a sort of “barcode.” The researchers then followed the patients for around two and a half years, and found that a group with one specific 9-gene “barcode” had a much lower survival rate.

Those results were also compared to 70 more patients from the Memorial Sloan kettering Cancer Centre, which confirmed the results. The research suggests, said the study’s authors, that cancer tumors release an “anomalous immune response” as they grow.

“The test we have developed is simpler and potentially more precise than many other tests we currently have available or than carrying out another biopsy”, said the study’s authors.

This study comes just days after a different study, published in the Journal of Urology, demonstrated a test that more effectively uses biopsies. That test looks for genetic markers as well, and could help prevent the number of follow-up biopsies doctors require from patients.